Paint overspray treatment compositions and methods of use

Abstract

Overspray treatment compositions for addition to a water source located within a paint overspray waterwash system located in a spray-paint booth, or a water source that is subsequently applied to such a paint overspray waterwash system for contact with a paint overspray include an amine-functionalized colloidal silica having about 0.1 μmol to 15.00 μmol of amine functionality per square meter of silica surface area, and optionally a coagulant. The compositions and methods described herein work within a pH range of 6.5 and 10 to provide treated paint oversprays. Addition of a flocculant to a treated overspray results in formation of associated complexes having low tack, which may be cleanly separated from the aqueous treatment residue. The aqueous treatment residue may be subjected to one or more additional cycles of use in the paint overspray waterwash system.

What is claimed is: 
     
         1 . An overspray treatment composition comprising a detackifier comprising an amine-functionalized colloidal silica; and a coagulant comprising a polyionic compound, an inorganic salt, or a combination thereof. 
     
     
         2 . The overspray treatment composition of  claim 1  wherein the coagulant is selected from aluminum sulfate/chloride, ferric chloride/sulfate, polyaluminum chloride, a water-soluble aluminum complex with the general formula Al n Cl (3n-m) (OH) m ; and combinations of two or more thereof. 
     
     
         3 . The overspray treatment composition of  claim 1  wherein the coagulant is Al 2 Cl(OH) 5 . 
     
     
         4 . The overspray treatment composition of  claim 1  wherein the amine-functionalized colloidal silica comprises about 0.1 μmol to 15.00 μmol of amine functionality per square meter of silica surface area. 
     
     
         5 . The overspray treatment composition of  claim 1  wherein the amine-functionalized colloidal silica is an amine-functionalized silica sol having a particle size between 10 nm and 100 nm. 
     
     
         6 . The overspray treatment composition of  claim 1  wherein the weight ratio of amine-functionalized colloidal silica solids to coagulant solids is about 1:10 to 20:1. 
     
     
         7 . A treated washwater comprising a water source and 0.01 ppm to 10,000 ppm by weight of an overspray treatment composition, the water source disposed within a paint overspray waterwash system; wherein the paint overspray treatment composition comprises an amine-functionalized colloidal silica. 
     
     
         8 . The treated washwater of  claim 7  further comprising 0.01 ppm to 1000 ppm by weight of a coagulant. 
     
     
         9 . The treated washwater of  claim 7  wherein the pH of the treated washwater is between 6.5 and 10. 
     
     
         10 . A method of treating a paint overspray, the method comprising
 adding an overspray treatment composition to a washwater located within a paint booth overspray waterwash system or operably connected to a paint booth overspray waterwash system, to form a treated washwater; and   operating the paint booth overspray waterwash system while spraying a paint within the paint booth, wherein the treated washwater is contacted with a paint overspray to form a treated overspray,   wherein the overspray treatment composition comprises an amine-functionalized colloidal silica and optionally a coagulant.   
     
     
         11 . The method of  claim 10  further comprising adding a flocculant to the treated overspray to form a flocculated overspray. 
     
     
         12 . The method of  claim 11  further comprising subjecting the flocculated overspray to solid-liquid separation to obtain one or more associated complexes and an aqueous treatment residue. 
     
     
         13 . The method of  claim 12  wherein the aqueous treatment residue is subjected to one or more cycles of use within the paint booth overspray waterwash system. 
     
     
         14 . The method of  claim 10  wherein the paint is a solvent-based paint. 
     
     
         15 . The method of  claim 10  wherein the paint is a water-based paint. 
     
     
         16 . A kit comprising
 an amine-functionalized colloidal silica;   a flocculant, and   instructions that direct a user to add 0.01 ppm to 10,000 ppm by weight of the amine-functional colloidal silica to either a water source located within a paint overspray waterwash system, or a water source that is subsequently applied to a paint overspray waterwash system.   
     
     
         17 . The kit of  claim 16  further comprising a coagulant. 
     
     
         18 . The kit of  claim 17  wherein the amine-functional colloidal silica and the coagulant are provided as a mixture thereof in a ratio of 1:10 to 20:1 by weight. 
     
     
         19 . The kit of  claim 17  wherein the coagulant is aluminum chloride hydroxide and the instructions further direct the user to add the coagulant to a water source in an amount of 0.01 ppm to 1000 ppm by weight. 
     
     
         20 . The kit of  claim 16  wherein the amine-functional colloidal silica and the flocculant are provided separately, and the instructions further direct the user to add the amine-functional colloidal silica and flocculant in a ratio of 1:10 to 200:1 by weight.